US4407591A - Ballistic wire matrix print head - Google Patents

Ballistic wire matrix print head Download PDF

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Publication number
US4407591A
US4407591A US06/292,173 US29217381A US4407591A US 4407591 A US4407591 A US 4407591A US 29217381 A US29217381 A US 29217381A US 4407591 A US4407591 A US 4407591A
Authority
US
United States
Prior art keywords
guide assembly
tube
pole piece
wires
cores
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/292,173
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English (en)
Inventor
Contardo Adamoli
Francesco Bernardis
Franco Cretaz
Mario Gaiardo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
C OLIVETTI & C SpA (ING)
Telecom Italia SpA
Original Assignee
Ing C Olivetti and C SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ing C Olivetti and C SpA filed Critical Ing C Olivetti and C SpA
Assigned to C. OLIVETTI & C., S.P.A., (ING) reassignment C. OLIVETTI & C., S.P.A., (ING) ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ADAMOLI, CONTARDO, BERNARDIS, FRANCESCO, CRETAZ, FRANCO, GAIARDO, MARIO
Application granted granted Critical
Publication of US4407591A publication Critical patent/US4407591A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
    • B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
    • B41J2/27—Actuators for print wires
    • B41J2/275—Actuators for print wires of clapper type

Definitions

  • This invention relates to a wire printing head of ballistic type, comprising a plurality of wires slidable axially in a guide, and which are projected by the armatures of a corresponding plurality of control electromagnets in order to effect printing.
  • a head of this type is known in which a group of seven or nine electromagnets is supported by a semicircular metal plate disposed transversely to the printing wires.
  • a resin block fixes the individual cores and the energising coils to the baseplate. Most of the radiating surface is therefore in resin, and this leads to considerable temperature rises in the most inner parts of the energising coils, especially when the number of electromagnets and/or their frequency of energisation are to be increased. This represents a serious limit to high speed printing.
  • the object of the invention is to provide a printing head which has a very compact structure while at the same time succeeding in properly dissipating the heat produced by the energisation of the coils of the electromagnets which control the wires.
  • the printing head comprises a supporting guide, a plurality of wires axially slidable in said guide, a corresponding plurality of control electromagnets having each one an armature connected to a corresponding wire, for the actuation thereof, and a tube of high thermal conductivity material having an inner wall, said electromagnets having magnetic cores spaced around and in contact with said inner wall of said tube.
  • FIG. 1 is a plan view of a wire printing head embodying the invention
  • FIG. 2 is a section on the line 2--2 of FIG. 1;
  • FIG. 3 is a partly sectional rear view of the printing head.
  • the printing head 10 comprises a front guide 11 of plastics material, inside which a plurality of metal printing wires 12 is mounted in an axially slidable manner (see also FIG. 2).
  • the wires are sixteen in number, and have their front printing ends 14 aligned in two parallel columns, which are offset from each other by one half of the wire-to-wire pitch, to provide high definition dot printing.
  • the printing wires can be seven or nine in number, and in this case have their printing ends aligned in a single column.
  • the guide 11 is shaped to comprise a base wall 15, a rear wall 16 and two side walls 17 and 18, between which are disposed transverse plates 19 provided with through bores, which guide the wires 12 by preventing them from moving laterally.
  • the printing ends 14 of the wires 12 are guided by a perforated plate 21 disposed on the front end of the guide 11.
  • each wire 12 (FIG. 2) is guided by said wall 16, and has its rear end rigidly connected to a head 26 of plastics material, with which there cooperates a spiral spring 27 which, when at rest, retains the corresponding wire 12 in an inoperative, withdrawn position.
  • a cover 28 is removably mounted on the guide 11.
  • each electromagnet 30 comprises a core 31 of ferromagnetic material shaped in the form of a U and provided with a leg 37 (FIGS. 2 and 3) of triangular cross-section and a leg 38 of rectangular cross-section, an energising coil 32 wound about the leg 37, and an armature 33 facing the pole faces 34 and 35 of the legs 37 and 38.
  • the cores 31 are produced for example by sintering ferromagnetic powders, this enabling the shape heretofore described to be obtained at low cost.
  • the cores 31 and coils 32 of all sixteen electromagnets 30 (FIG. 3) are spaced around the inside a tube 36 of a non-magnetic material having high thermal conductivity, for example sintered aluminium, and are embedded in a single resin block 39 which adheres to the interior of the tube 36.
  • the tube 36 is shaped in such a matter as to possess internal axial seats 40 equidistant angularly from each other, into which the legs 38 of the cores 31 are fitted, and to comprise external radial fins 41 for better dissipation of the heat developed by the electromagnets 30 during the operation of the head 10.
  • a printed circuit 42 containing the supply strips for the coils 32 is also embedded in the resin block 39, and its lower part 43, which comprises the terminals of the supply strips, is arranged for connection to an edge connector.
  • the resin block 39, the aluminium tube 36, the printed circuit 42, the cores 31 and coils 32 constitute a single homogeneous unit 44 (FIG. 1) which can be preassembled in the manner described in detail hereinafter.
  • the resin block 39 (FIG. 2) has a central through bore 47 in which the rear end of the guide 11 is housed. In order to prevent relative rotation between the unit 14 and the guide 11, this latter is provided with a lower key 48 housed in a corresponding slot 49 in the block 39.
  • the position of the guide 11 in the axial direction relative to the unit 44 is determined by a transverse shoulder 50 of the guide 11, which is arranged to abut against a front wall 51 of the resin block 39, by way of one or more removable shim discs 52, each having a predetermined thickness, for example one hundredth of a millimeter.
  • the armatures 33 of all the sixteen electromagnets 30 are arranged, angularly equidistant from each other, inside a single rear plastics support 55, which is of substantially cylindrical shape and has its base 54 connected to the guide 11 by means of a screw 56 and a capping nut 57.
  • Each armature 33 has an inner end 58 (FIG. 3) which is tapered and guided between two elements 59 of the support 55. Each end 58 is constantly in contact with a corresponding head 26 of a printing wire 12.
  • the armatures 33 are kept inclined to the pole surfaces 34 and 35 of the cores 31 by the action of the spiral springs 27.
  • a disc 63 of plastics material for example Mylar (Trade Mark), having a thickness of a few hundredths of a millimeter, is disposed between the magnetic cores 31 and armatures 33, and always rests against the pole faces 34 and 35 to precisely define the minimum gap between the armatures and cores.
  • Mylar Trade Mark
  • the rear support 55 has two fins 65 (FIG. 1) inserted between two shoulders 66 and 67 of the aluminium tube 36, in order to angularly position said support 55 relative to the unit 44, and prevent relative rotation between these two latter.
  • the previously described unit 44 is assembled in the following manner.
  • the printed circuit 42 (FIGS. 2 and 3) is fixed to the front end of the aluminium tube 36 in any known manner, for example by screws not shown on the drawings.
  • the legs 38 of the magnetic cores 31 (FIG. 3) are then inserted into the respective seats 40.
  • energising coil 32 is then inserted over each inner pole piece or leg 37 of the cores 31, and its ends are soldered to the underlying conducting strips of the printed circuit 42.
  • the elements associated in this manner are finally embedded in the insulating resin forming the block 39, which is then further machines in order to assume the described shape shown on the drawings.
  • a frontal rear surface 69 opposite the front wall 51 is ground such that all the pole faces 34 and 35 lie in a single plane perpendicular to the axis of the tube 36, and without any projections.
  • the disc 63 which is disposed between the cores 31 and armatures 33, lies in a single plane and has no preferential zones of drawing, and thus of fracturing.
  • the bore 47 is also ground in order to guide the front guide 11 with precision.
  • the printing head 10 described heretofore is arranged for mounting on a carriage 70 (FIGS. 1 and 2) of a serial printer of known type, for example of the type described in our U.S. patent application Ser. No. 06/267,911 filed on May 28, 1981 and assigned to the same assignee as the present application.
  • the carriage 70 can be constructed of plastics material, and is slidable on guides 71 parallel to a platen 72.
  • the base wall 15 of the guide 11 is provided with two cylindrical pins 74 to be inserted into corresponding bores 75 in the carriage 70.
  • Three screws 76 are provided for removably fixing on to the carriage 70 the head 10 positioned by the pins.
  • the operation of the printing head 10 takes place in known manner by moving the carriage 70 parallel to the platen 72 and selectively actuating the electromagnets 30 which cause the wires 12 to transfer ink from a ribbon 77, disposed between the printing ends 14 of the wires 12 and platen 72, on to a sheet 78 carried by the platen 72. More precisely, each time one of the coils 32 is fed with current, a magnetic flux is generated in the core 31, which causes the corresponding armature 33 to be attracted towards the pole faces 34 and 35. This leads to the axial movement of the wire 12 associated therewith, and this continues its path of travel towards the platen 72 ballistically, even after the armature 33 has been halted against the disc 63 disposed between it and the core 31.
  • the reaction force causes the wire 12 to return towards its rest position.
  • the spring 27 returns the wire 12 and armature 33 to rest, against the resilient ring 62.
  • the printing head 10 embodying the invention it is possible to vary the distance of all sixteen wires 12 from the platen 72 without removing the head from the carriage 70.
  • the distance of the wires 12 from the platen 72 is respectively increased or decreased, while maintaining the conditions between the wires 12 and actuating electromagnets 30 unchanged.
US06/292,173 1980-08-21 1981-08-12 Ballistic wire matrix print head Expired - Lifetime US4407591A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT68304/80A IT1128976B (it) 1980-08-21 1980-08-21 Testina di stampa a fili balistica
IT68304A/80 1980-08-21

Publications (1)

Publication Number Publication Date
US4407591A true US4407591A (en) 1983-10-04

Family

ID=11308917

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/292,173 Expired - Lifetime US4407591A (en) 1980-08-21 1981-08-12 Ballistic wire matrix print head

Country Status (6)

Country Link
US (1) US4407591A (de)
JP (1) JPS5772872A (de)
DE (1) DE3133083A1 (de)
FR (1) FR2488834B1 (de)
GB (1) GB2082508B (de)
IT (1) IT1128976B (de)

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4453840A (en) * 1982-12-06 1984-06-12 Hodne Ingard B Actuator for a print wire
US4525089A (en) * 1982-02-03 1985-06-25 C. Olivetti & C., S.P.A. Document feed-in device
US4548521A (en) * 1983-12-09 1985-10-22 Ncr Corporation Dot matrix print head
US4572681A (en) * 1982-11-12 1986-02-25 Epson Corporation Wire dot print head
US4629343A (en) * 1983-10-14 1986-12-16 Ing. C. Olivetti & C., S.P.A. Matrix printing device
US4632580A (en) * 1985-03-25 1986-12-30 Ncr Corporation Dot matrix print head dampening mechanism
US4634303A (en) * 1985-08-26 1987-01-06 Dataproducts, Inc. Actuator for dot matrix printhead
US4661002A (en) * 1983-08-19 1987-04-28 Canon Kabushiki Kaisha Dot matrix printer
US4681467A (en) * 1985-04-23 1987-07-21 International Business Machinces Corporation Impact printing applications
US4772141A (en) * 1982-10-27 1988-09-20 Royden C. Sanders, Jr. Dot matrix printhead pin driver and method of assembly
US4778297A (en) * 1985-11-08 1988-10-18 Hitachi Koki Company, Limited Hammer coil cooling means in line printer
WO1988008792A1 (en) * 1987-05-08 1988-11-17 Protechno Ces Gmbh & Co. Kg Matrix printing head with swinging-armature magnets
US4795283A (en) * 1986-10-14 1989-01-03 Citizen Watch Co., Ltd. Print head for a dot-printer
US4810112A (en) * 1986-07-25 1989-03-07 Microlys S.P.A. Dot matrix print head of improved type
US4818133A (en) * 1986-05-16 1989-04-04 Williams Richard A High speed wire matrix print head
US4840501A (en) * 1986-04-29 1989-06-20 Dataproducts Corporation Three pole printhead actuator
EP0323418A2 (de) * 1987-12-29 1989-07-05 Ing. C. Olivetti & C., S.p.A. Nadeldrucker und Verfahren zu dessen Zusammenbau
EP0371182A1 (de) * 1988-12-01 1990-06-06 MANNESMANN Aktiengesellschaft Matrixnadeldruckkopf der Klappankerbauart
EP0371183A1 (de) * 1988-12-01 1990-06-06 MANNESMANN Aktiengesellschaft Matrixnadeldruckkopf der Klappankerbauart
US4976553A (en) * 1987-12-09 1990-12-11 Max Co., Ltd. Very small displacement enlargement mechanism and printing head using the same
US4995742A (en) * 1988-10-18 1991-02-26 Bull Hn Information Systems, Inc. Needle printing head
US5039239A (en) * 1988-08-01 1991-08-13 Mannesmann Aktiengesellschaft Matrix pin-print head of the hinged-clapper-armature construction
US5149213A (en) * 1990-07-11 1992-09-22 Brother Kogyo Kabushiki Kaisha Noise reducing back stopper for an impact print head
US5156469A (en) * 1990-12-18 1992-10-20 Seiko Epson Corporation Impact dot printer
CN1090099C (zh) * 1997-04-18 2002-09-04 潘尼尼股份公司 一种打印头
US20080166166A1 (en) * 2007-01-04 2008-07-10 Viktors Berstis Method and apparatus for perforating a printable surface

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3243476A1 (de) * 1982-11-22 1984-05-24 Mannesmann AG, 4000 Düsseldorf Nadeldruckkopf fuer matrixdrucker
DE3243475A1 (de) * 1982-11-22 1984-05-24 Mannesmann AG, 4000 Düsseldorf Nadeldruckkopf fuer matrixdrucker
US4502799A (en) * 1983-02-25 1985-03-05 Ncr Corporation Dot matrix print head
IT1163942B (it) * 1983-09-27 1987-04-08 Honeywell Inf Systems Gruppo elettromagnetico di stampa per stampante a mosaico
EP0157624A3 (de) * 1984-03-30 1987-07-29 Nec Home Electronics, Ltd. Druckkopfreihe und deren Herstellungsverfahren
JPS6164459A (ja) * 1984-09-07 1986-04-02 Citizen Watch Co Ltd ドツトラインプリンタの印字ヘツド
JPS621551A (ja) * 1985-06-28 1987-01-07 Toshiba Corp 印字ヘツド装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770092A (en) * 1972-02-14 1973-11-06 Autotronics Inc Wire print head
US3896918A (en) * 1971-03-04 1975-07-29 Winfried Schneider Mosaic printing head with electromagnetically actuated needles with a common yoke for all electromagnets
US3929214A (en) * 1974-09-18 1975-12-30 D & D Ass Wire matrix ballistic impact print head
US4004673A (en) * 1974-06-25 1977-01-25 The Singer Company Wire matrix printhead having facility for enabling wirewear correction
US4049107A (en) * 1974-10-08 1977-09-20 Societe D'applications Generales D'electricite Et De Mecanique Sagem Printing devices or heads for printers or the like and a process for making such a printing head
US4165940A (en) * 1977-02-28 1979-08-28 Centronics Data Computer Corp. Free flight head assembly for dot matrix printers and the like

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE8005330U1 (de) * 1980-06-04 Triumph Werke Nuernberg Ag, 8500 Nuernberg Vorrichtung zur Wärmeabführung bei Nadeldruckköpfen
DE1611431C3 (de) * 1967-11-10 1975-08-14 Johann 8100 Garmisch- Partenkirchen Distl Drahtdruckkopf
DE2119641C3 (de) * 1971-04-22 1975-05-15 Anker-Werke Ag, 4800 Bielefeld Schreibkopf für Nadeldruckwerke
JPS5516834B2 (de) * 1971-11-20 1980-05-07
GB1436885A (en) * 1973-06-29 1976-05-26 Autotronics Inc Wire printing devices
DE2335547A1 (de) * 1973-07-12 1975-01-30 Autotronics Inc Vorrichtung zum drahtdrucken
JPS5736437Y2 (de) * 1976-04-09 1982-08-11
DE2807337A1 (de) * 1977-02-22 1978-08-31 Information Magnetics Corp Matrixdruckerkopf
CA1096234A (en) * 1977-06-13 1981-02-24 Harold A. Long Wear minimizing means for printing mechanism
WO1979000738A1 (en) * 1978-03-10 1979-10-04 Dh Ass Matrix print head assembly

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3896918A (en) * 1971-03-04 1975-07-29 Winfried Schneider Mosaic printing head with electromagnetically actuated needles with a common yoke for all electromagnets
US3770092A (en) * 1972-02-14 1973-11-06 Autotronics Inc Wire print head
US4004673A (en) * 1974-06-25 1977-01-25 The Singer Company Wire matrix printhead having facility for enabling wirewear correction
US3929214A (en) * 1974-09-18 1975-12-30 D & D Ass Wire matrix ballistic impact print head
US4049107A (en) * 1974-10-08 1977-09-20 Societe D'applications Generales D'electricite Et De Mecanique Sagem Printing devices or heads for printers or the like and a process for making such a printing head
US4165940A (en) * 1977-02-28 1979-08-28 Centronics Data Computer Corp. Free flight head assembly for dot matrix printers and the like

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4525089A (en) * 1982-02-03 1985-06-25 C. Olivetti & C., S.P.A. Document feed-in device
US4772141A (en) * 1982-10-27 1988-09-20 Royden C. Sanders, Jr. Dot matrix printhead pin driver and method of assembly
US4572681A (en) * 1982-11-12 1986-02-25 Epson Corporation Wire dot print head
US4453840A (en) * 1982-12-06 1984-06-12 Hodne Ingard B Actuator for a print wire
US4661002A (en) * 1983-08-19 1987-04-28 Canon Kabushiki Kaisha Dot matrix printer
US4629343A (en) * 1983-10-14 1986-12-16 Ing. C. Olivetti & C., S.P.A. Matrix printing device
US4548521A (en) * 1983-12-09 1985-10-22 Ncr Corporation Dot matrix print head
US4632580A (en) * 1985-03-25 1986-12-30 Ncr Corporation Dot matrix print head dampening mechanism
US4681467A (en) * 1985-04-23 1987-07-21 International Business Machinces Corporation Impact printing applications
US4634303A (en) * 1985-08-26 1987-01-06 Dataproducts, Inc. Actuator for dot matrix printhead
US4778297A (en) * 1985-11-08 1988-10-18 Hitachi Koki Company, Limited Hammer coil cooling means in line printer
US4840501A (en) * 1986-04-29 1989-06-20 Dataproducts Corporation Three pole printhead actuator
US4818133A (en) * 1986-05-16 1989-04-04 Williams Richard A High speed wire matrix print head
US4810112A (en) * 1986-07-25 1989-03-07 Microlys S.P.A. Dot matrix print head of improved type
US4795283A (en) * 1986-10-14 1989-01-03 Citizen Watch Co., Ltd. Print head for a dot-printer
EP0293638A1 (de) * 1987-05-08 1988-12-07 protechno CES GmbH & Co. KG Nadeldruckkopf mit Klappankermagneten
WO1988008792A1 (en) * 1987-05-08 1988-11-17 Protechno Ces Gmbh & Co. Kg Matrix printing head with swinging-armature magnets
US4988223A (en) * 1987-05-08 1991-01-29 Protechno Ces Gmbh & Co Kg Matrix printing head with pivotable armatures
US4976553A (en) * 1987-12-09 1990-12-11 Max Co., Ltd. Very small displacement enlargement mechanism and printing head using the same
EP0323418A3 (en) * 1987-12-29 1989-08-30 Ing. C. Olivetti & C., S.P.A. A printer with wires or needles and a method for its assembly
EP0323418A2 (de) * 1987-12-29 1989-07-05 Ing. C. Olivetti & C., S.p.A. Nadeldrucker und Verfahren zu dessen Zusammenbau
US4995743A (en) * 1987-12-29 1991-02-26 Ing. C. Olivetti & C., S.P.A. Wire printer with step formation armature and method of assembly
US5039239A (en) * 1988-08-01 1991-08-13 Mannesmann Aktiengesellschaft Matrix pin-print head of the hinged-clapper-armature construction
US4995742A (en) * 1988-10-18 1991-02-26 Bull Hn Information Systems, Inc. Needle printing head
EP0371183A1 (de) * 1988-12-01 1990-06-06 MANNESMANN Aktiengesellschaft Matrixnadeldruckkopf der Klappankerbauart
EP0371182A1 (de) * 1988-12-01 1990-06-06 MANNESMANN Aktiengesellschaft Matrixnadeldruckkopf der Klappankerbauart
US5149213A (en) * 1990-07-11 1992-09-22 Brother Kogyo Kabushiki Kaisha Noise reducing back stopper for an impact print head
US5156469A (en) * 1990-12-18 1992-10-20 Seiko Epson Corporation Impact dot printer
CN1090099C (zh) * 1997-04-18 2002-09-04 潘尼尼股份公司 一种打印头
US20080166166A1 (en) * 2007-01-04 2008-07-10 Viktors Berstis Method and apparatus for perforating a printable surface

Also Published As

Publication number Publication date
IT1128976B (it) 1986-06-04
DE3133083A1 (de) 1982-04-01
JPH032672B2 (de) 1991-01-16
FR2488834B1 (fr) 1987-05-22
IT8068304A0 (it) 1980-08-21
GB2082508B (en) 1984-09-05
GB2082508A (en) 1982-03-10
JPS5772872A (en) 1982-05-07
FR2488834A1 (fr) 1982-02-26
DE3133083C2 (de) 1992-09-03

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